xv GUIANA PIG AND RESTLESS CAW 493 _ _________________________________________ 3& in the river, furnished with open water, and also beds of * eamelotes/—a sloping open grassy bank on one side, where the Garpinchos can lie in the daytime in the cooler weather, sleeping and basking in the sunshine; on the other a low shelving bank, clothed with * Sarandi" scrub growing out into the black reeking mud and shallow water beyond." They always take to the water when alarmed, at a rate and with a gait which reminded Mr. Aplin of a Pig. When in the water they swim slowly with the upper part of the head, including nose, eyes, and ears, above the surface. But they can dive for a considerable time and distance, and baffle their enemies by seeking the shelter of a mass of water-plants, and lying there with their, noses only just above the surface. The genus Dolichotis * has long ears, and generally resembles a rather long-legged Hare in appearance. The front-feet are four- toed, the hind three-toed. The Patagonian Cavy, as this animal is called, has twelve dorsal vertebrae, and rudimentary clavicles.2 The paroccipital processes are long ; the incisors are white, and are not grooved in front. The sternum has six pieces, and seven ribs reach it. Co/da, including the species O. yorcellus, the Guinea-pig (which name is a corruption apparently of Guiana pig)> has the same number of toes on its hind- and fore-feet as has the Capybara. The name applied to the wild stock whence our Guinea-pig is derived is the Restless Cavy. The fur is greyish ; of the domestic animals the colour is too well known to need description. Fam. 4. Dasyproctidae.—The genus Coelogenys includes but two species. G. paca, known as the "Spotted Cavy" or "Paca," has a brown body, with white spots like those of a Dasyure ; it is one of the largest of Rodents, and has a quite short tail. The hand and foot are both provided with five digits; but the thumb is small, and in the foot the three middle toes considerably exceed the others in length. The hind-foot is practically three-toed. The fibula is not nearly so reduced as in DolicJiotis. The skull of the animal is remarkable for the extraordinary development in breadth of the jugal arch, which is sculptured externally. There is a large cavity formed below, at the maxillary end of this huge 1 Beddard, Proc. Zool. Soc. 1891, p. 236. a These are stated by Tnllberg to be absent. I have found them, but they are very small bones, not more than half an inch long.